1. 1 ENIAC TX-0 IBM 360 Osborne I Libretto 110CT (1946) (1956) (1964) (1981) Today System miniaturization brings us: function enhance more reliable save material and energy cost down 第一台电子管计算机 第一台晶体管计算机 第一台集成电路计算机 第一台便携式计算机

2. 2 Look into the MEMS MEMS is never a science category but a technical solution for many application fields. However, MEMS needs many categories of scientific and engineering knowledge MEMS is Art and Science, needs not only IQ but also EQ Along with shrinking from Macro-machine to MEMS : 1.The most knowledge already existing 2. But two things adapting mechanics to micro scale that are of great importance in MEMS 1) Electrostatic effect; 2) Air damping control

3. 3 The work initiated by Bill Tang and Roger Howe should have been cited for many times. But actually no people would like to do so. Comb-drive Electrostatic Effect

4. 4 Liquid Manipulation Using ElectroWetting On Dielectric (EWOD) by C-J Kim et al ， UCLA

5. 5 Wanted Electrostatic Driving Electric Tuning k m > 0, k e < 0 f 0 = [(k m - k e )/m] 1/2 Electric feedback damping conditioning -k e / k m =   ’ =  /(1+  ) 1/2 f 0 ’ = f 0 (1+  ) 1/2 C Electric feedback

6. 6 So now you know: How does E and M couple each other in MEMS

7. 7 Electrostatic Pull-in Xinxin Li et al, J. Micomech. Microeng., 2000

8. 8 offset : sensitivity : nonlinearity : Avoiding in MEMS Sensor MH Bao et al, Sens. Actuators, 2002

9. 9 Improvement: Push-pull balance and feedback loop

10. 10 17µm DMD by TI Positive utilization of Pull-in H Yang et al, IEEE SENSORS 2005

11. 11 Problem in existing Christian Model for rare air or low vacuum Air damping MH Bao et al, J. Micromech. Microeng. 2003

12. 12 Bao Model based on energy method 1. Energy method for Q, with test verification 2. Influenced by adjacent electrode considered 3. Related to geometry Christian Model 1. Momentum method for Q ， big difference from testing results 2. That not considered 3. That not related

13. 13 I － test ， II － Christian ， III － Bao model

14. 14 Hole radius r o Equivalent cell radius r c =ro/rc=ro/rc Modified Reynolds Equation for squeeze film damping of perforated plate structure MH Bao et al, J. Micromech. Microeng. 2002

15. 15

16. 16

17. 17 So now you know: Why I chose this Bao’s textbook for your course Now I assign the 1st homework: pre-reading

18. 18 The 2nd part of your homework: Thinking about 1.What is MEMS by your thinking? try to give your own definition. try your best to use four English words with their capitals in the order of M, E, M and S For example: Miniaturized Everything Making Sense 2. Why people use MEMS? i.e. the advantage of MEMS 3. Who is the Korean researcher doing micro-fluidic bio-MEMS? And who does NEMS probes 4. How MEMS can be put into volume production? i.e. make big money 5. Which kind of MEMS work you are the most interested in?